Mesoscale climatic impacts on the distribution of Homarus americanus in the US inshore Gulf of Maine

American lobster (Humana americanus) supports one of the most valuable fisheries in the United States. Spatial distributions of H. americanus are hypothesized to be influenced by climate-driven environmental factors, but such effects have not been quantified. We developed a Tweedie generalized additive model (GAM) to quantify environmental effects on season-, sex-, and size-specific distributions of H. americanus in the inshore Gulf of Maine. Tweedie GAMS were coupled with regional circulation model output to predict spatiotemporal changes in distribution ofH. americanus due to mesoscale climate variability. GAM results indicated that bottom temperature and salinity impacts on H. americanus distribution were more pronounced during spring. The coupled climate-niche model predicted significantly higher H. americanus abundance under a warm climatology scenario. This study provides a predictive climate-niche modelling framework that may be useful for planning fishery investments and anticipating management challenges given ongoing climate-driven changes in the Northwest Atlantic.